THEORY OF ULTRASONIC ATTENUATION BY MAGNETIC SURFACE STATES IN METALS

A theoretical expression for the resonant absorption of longitudinal ultrasound by magnetic surface states is given, and the basic physical ideas are explained. The interaction matrix element showing quasi‐geometric oscillations is calculated and discussed, and the order of magnitude of the absorption is estimated. The experimental realization of the effect appears to be very difficult. From the theoretical point of view it is pointed out that on favourable conditions such ultrasonic investigations should be more convenient for determining the relevant physical parameters than microwave experiments. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim